Kidney health outcomes of hypertensive disorders of pregnancy.

Hypertensive disorders of pregnancy (HDPs), including pre-eclampsia (PE), are frequent, affecting 8-10% and 2-4% of all pregnancies, respectively. Among HDPs, PE is the best characterized and most frequently studied - it is a heterogeneous disease with different clinical phenotypes reflecting distinct underlying mechanisms that ultimately result in widespread endothelial dysfunction and systemic damage. HDP clinical remission is common after delivery, but the long-term health of women with a history of HDP is adversely affected compared with that of women with normotensive pregnancies. The relationship between HDP and kidney health is bidirectional: chronic kidney disease (CKD) increases the risk of HDP, and HDP raises the risk of future CKD. To what extent this increased risk of CKD after HDP is due to pre-existing CKD that is unmasked by pregnancy and/or whether HDP is a causal factor in CKD remains unclear. CKD is diagnosed in up to 20% of women after PE, and the lifetime risk of kidney failure after one episode of PE is 4-8 times higher than that of the general population, increasing further with PE recurrence. These risks are cross generational, as women born prematurely from pregnancies complicated by PE and fetal growth restriction can have low nephron mass, which would not only increase their lifetime risk of CKD but also their risk of developing PE in their own pregnancies.